Hongshun Li

Low-velocity Impact Behaviour of 3-D Glass Fibre Hollow Integrated Core Sandwich Composites

In the current work, 3-D glass fibre woven fabric-reinforced composites were fabricated by impregnating epoxy resin in a hand lay-up procedure for the hollow integrated core sandwich structure. Four types of 3-D structures were investigated in terms of the impact properties as a function of the z-direction fibre length (5, 6 and 7 mm) and covered skins (covered with aluminium) in core structures. Impact properties including peak load, time to peak load, and absorbed energy were evaluated. It was found that the 3-D hollow integrated core sandwich composites covered with aluminium skin considerably enhanced the impact resistance. Photographs of the impact damage taken after impact tests were analyzed and discussed in terms of a hollowing on the front face sheet against the load applied, and whitening spread in the impact point on the back face sheet of the composites was also studied.

Finite element analysis of the compressive properties of 3-D hollow integrated sandwich composites

On the basis of previous studies, the structural model of 3-D hollow integrated sandwich composites for the compressive analysis was built by using the finite element software ANSYS. In the paper, the influence of pile height (6, 8 and 10 mm), pile density (4, 6 and 8 mm), elastic modulus (36, 38 and 40 GPa) and poisson ratio (0.30, 0.35 and 0.40) of the 3-D composites on the compressive properties were studied, and the effects of these factors were analyzed and discussed. The results revealed that the maximum value of the stress appeared in the interface between the piles and the face-sheets when the 3-D composites were subject to compressive loads, in which the composites damaged easily. The compressive properties of the 3-D composites increased with the increase of the pile density and poisson ratio, and decreased with that of the pile height. Elastic modulus has little influence on the compressive properties of the 3-D composites. The study provides a reference for the structural optimum of the 3-D composites.